3 files changed, 71 insertions, 0 deletions

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index 1e070a2b561a..7bcd69a9a88c 100644
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -150,6 +150,14 @@
 #endif
 
 /*
+ * Amount of memory reserved for the vmalloc() area, and minimum
+ * address for vmalloc mappings.
+ */
+extern unsigned long vmalloc_reserve;
+
+#define VMALLOC_MIN             (void *)(VMALLOC_END - vmalloc_reserve)
+
+/*
  * PFNs are used to describe any physical page; this means
  * PFN 0 == physical address 0.
  *
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 38f0e7940a13..2ca7038b67a7 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -81,6 +81,8 @@ EXPORT_SYMBOL(system_serial_high);
 unsigned int elf_hwcap;
 EXPORT_SYMBOL(elf_hwcap);
 
+unsigned long __initdata vmalloc_reserve = 128 << 20;
+
 
 #ifdef MULTI_CPU
 struct processor processor;
@@ -501,6 +503,17 @@ static void __init early_mem(char **p)
 __early_param("mem=", early_mem);
 
 /*
+ * vmalloc=size forces the vmalloc area to be exactly 'size'
+ * bytes. This can be used to increase (or decrease) the vmalloc
+ * area - the default is 128m.
+ */
+static void __init early_vmalloc(char **arg)
+{
+        vmalloc_reserve = memparse(*arg, arg);
+}
+__early_param("vmalloc=", early_vmalloc);
+
+/*
  * Initial parsing of the command line.
  */
 static void __init parse_cmdline(char **cmdline_p, char *from)
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 2d6d682c206a..25d9a11eb617 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -568,6 +568,55 @@ void __init iotable_init(struct map_desc *io_desc, int nr)
                 create_mapping(io_desc + i);
 }
 
+static int __init check_membank_valid(struct membank *mb)
+{
+        /*
+         * Check whether this memory region has non-zero size.
+         */
+        if (mb->size == 0)
+                return 0;
+
+        /*
+         * Check whether this memory region would entirely overlap
+         * the vmalloc area.
+         */
+        if (phys_to_virt(mb->start) >= VMALLOC_MIN) {
+                printk(KERN_NOTICE "Ignoring RAM at %.8lx-%.8lx "
+                        "(vmalloc region overlap).\n",
+                        mb->start, mb->start + mb->size - 1);
+                return 0;
+        }
+
+        /*
+         * Check whether this memory region would partially overlap
+         * the vmalloc area.
+         */
+        if (phys_to_virt(mb->start + mb->size) < phys_to_virt(mb->start) ||
+            phys_to_virt(mb->start + mb->size) > VMALLOC_MIN) {
+                unsigned long newsize = VMALLOC_MIN - phys_to_virt(mb->start);
+
+                printk(KERN_NOTICE "Truncating RAM at %.8lx-%.8lx "
+                        "to -%.8lx (vmalloc region overlap).\n",
+                        mb->start, mb->start + mb->size - 1,
+                        mb->start + newsize - 1);
+                mb->size = newsize;
+        }
+
+        return 1;
+}
+
+static void __init sanity_check_meminfo(struct meminfo *mi)
+{
+        int i;
+        int j;
+
+        for (i = 0, j = 0; i < mi->nr_banks; i++) {
+                if (check_membank_valid(&mi->bank[i]))
+                        mi->bank[j++] = mi->bank[i];
+        }
+        mi->nr_banks = j;
+}
+
 static inline void prepare_page_table(struct meminfo *mi)
 {
         unsigned long addr;
@@ -753,6 +802,7 @@ void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
         void *zero_page;
 
         build_mem_type_table();
+        sanity_check_meminfo(mi);
         prepare_page_table(mi);
         bootmem_init(mi);
         devicemaps_init(mdesc);